Of course, we don’t really know whether dark energy even exists. What we do know is that the universe has been expanding since the big bang. But rather than slowing down like everything else fighting gravity’s pull, this expansion seems to be speeding up. Something must be causing this, and astronomers call that something dark energy. The hope is that scientists can use detailed photos to chart the light from galaxies and supernovas, which will show the growth of the cosmos and at least give them more evidence for the existence and effect of dark energy.